Unvented vs vented cylinder

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If you knew anything about heating and water system you would come out with such an inane silly comment. So best not comment on fields you know little. Maybe drains is your forte.
Thankyou for that hard..Thermal stores are still a load of crap.
Says the imbecile who drones on and on and on about Intergas boilers.
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People up and down the country must be rejoicing in this weather that they have a Gledhill pile of crap sat in the corner producing heat 24/7.
Yes, just like an unvented cylinder.
Must admit,not seen many unvented with a header tank full of hot water sat on top,but those gledhill systemate piles of crap produce some serious humidity!!.
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Hard work....
Keep to facts and avoid personal insults. Then the thread may run long enough for the facts to be fully explored.
Bernard you are right - let the idiots babble away. They are fun. Their ignorance and silliness makes me larf. It does. Look at the post just above this one. :) :)
then perhaps you ( hard work ) can explain why the operation of an un-vented [ cylinder ] would need ( or could be improved ) by a header tank being involved.
Bernard in a normal domestic house, I have tried but cannot. I really cannot. I did larf though. :)
With a hot water only thermal store that does not apply as you will use a diverter valve.
Agreed, that would be necessary if you want weather compensation, as I suggested in #52.
If you want a CH & DHW thermal store and weather compensation, then fit a stand alone compensator and modulating valve, which will be expensive as you are moving into commercial, and use a cheaper basic no frills boiler to heat it. Or, when the flow switch is activated have it also energise a relay which either cuts out the outside sensor or bypasses it giving zero resistance (depending on outside sensor), sending the boiler to maximum temperature. So when DHW is called full heat is sent from the boiler to the top of the cylinder, to be drawn off and sent to the DHW plate heat exchanger.

I don't see why it has to be complicated and expensive. Just use an ordinary diverter valve and go to full temperature when HW is calling. Just like when using a conventional HW cylinder.
On the other point, it looks to me like a mid-position valve is no use with weather compensation, as when both HW and CH are calling it would need to go to full temperature, negating the weather compensation, or move to the HW position so behaving as an either/or valve. I've never been keen on them anyway.

Have the CH flow tapped off the cylinder about a third down the cylinder.
I don't follow that, I thought in this arrangement the HW and CH circuits are separate.

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